Tack is an important property of a PSA as it quantifies its ability to form instantly a bond when brought into contact with a surface. The final adhesion and cohesive strength of the bond are influenced by numerous factors including the surface energies of the adhesive and substrate, dwell time, contact pressure, mechanical properties of the adhesive, as well as environmental conditions such as temperature and humidity [8]. Therefore, tack is important in many applications where an instant bond is required, however it is equally important when a ‘clean’ separation of the initially bonded surfaces is desirable. Many different methods for measuring the tack have been devised with the four main ones being the rolling ball, loop tack, quick stick and probe tack tests [9]. Each has its own advantages and disadvantages and the specific testing method should be selected based on the particular application.
